A Single-Step Synthesis of 4-Oxazolin-2-ones and Their Use in the Construction of Polycyclic Structures Bearing Quaternary Stereocenters
作者:Blanca M. Santoyo、Carlos González-Romero、Omar Merino、Rafael Martínez-Palou、Aydeé Fuentes-Benites、Hugo A. Jiménez-Vázquez、Francisco Delgado、Joaquín Tamariz
DOI:10.1002/ejoc.200900114
日期:2009.5
for the synthesis of 4-oxazolin-2-ones by a one-pot MW-promoted condensation of α-ketols and isocyanates is reported. An alternative thermal approach using the same starting materials is also described. These cyclic enamides were efficient nucleophiles, reacting with Michael acceptors and prenyl bromide to give a variety of polycyclicstructuresbearing one or two quaternarystereocenters. The selectivity
Divergent Pd-catalyzed Functionalization of 4-Oxazolin-2-ones and 4-Methylene-2-oxazolidinones and Synthesis of Heterocyclic-Fused Indoles
作者:Daniel Yescas-Galicia、Rodrigo A. Restrepo-Osorio、Ailyn N. García-González、Roberto I. Hernández-Benítez、José C. Espinoza-Hicks、Carlos H. Escalante、Edson Barrera、Blanca M. Santoyo、Francisco Delgado、Joaquín Tamariz
DOI:10.1021/acs.joc.2c01563
日期:2022.10.7
Palladium-catalyzed functionalization was presently performed on two building blocks: 4-oxazolin-2-ones and 4-methylene-2-oxazolidinones. Direct Heck arylation of 4-oxazolin-2-ones led to a series of 5-aryl-4-oxazolin-2-ones, including analogues with N-chiral auxiliary, in an almost quantitative yield. The Pd(II)-catalyzed homocoupling reaction of 4-oxazolin-2-ones provided novel heterocyclic across-ring
Regioselective Synthesis of N-Substituted 4-Methylene-2-oxazolidinones and 4-Oxazolin-2-ones. Study of Reactivity in Thermal Michael Conjugate Additions
作者:Rafael Martı́nez、Hugo A. Jiménez-Vázquez、Joaquı́n Tamariz
DOI:10.1016/s0040-4020(00)00311-2
日期:2000.6
N-Substituted 4-methylene-2-isoxazolidinones 9a–9e have been prepared from the tandem condensation of isocyanates 3 with α-ketol 7. In a more polar solvent (DMF) the same reaction led to stereoisomeric alcohols 11 and 12, which could be transformed to the thermodynamically more stable isomers 4-oxazolin-2-ones 10 in good yield. Thermal conjugate additions of both heterocycles 9a and 10a to enone 13
Synthesis of Diarylamines and Methylcarbazoles and Formal Total Synthesis of Alkaloids Ellipticine and Olivacine
作者:Edson Barrera、R. Israel Hernández‐Benitez、Carlos A. González‐González、Carlos H. Escalante、Aydeé Fuentes‐Benítes、Carlos González‐Romero、Elvia Becerra‐Martínez、Francisco Delgado、Joaquín Tamariz
DOI:10.1002/ejoc.202200364
日期:2022.6.27
A versatile and efficient methodology for the synthesis of 1-methyl and 1,4-dimethyl 3-formylcarbazoles is described. Microwave-promoted one-pot cascade reactions of 4-oxazolin-2-ones afforded methylated diarylamines, which were cyclized into a series of carbazoles, including the formaltotalsynthesis of the naturally occurring pyrido[4,3-b]carbazole alkaloids ellipticine and olivacine.
描述了一种用于合成 1-甲基和 1,4-二甲基 3-甲酰基咔唑的通用且有效的方法。微波促进 4-恶唑啉-2-酮的一锅级联反应得到甲基化二芳基胺,将其环化成一系列咔唑,包括天然存在的吡啶并[4,3- b ]咔唑生物碱玫瑰树碱的正式全合成和橄榄素。